Bug 265038

Summary:	Canvas rendering is janky
Product:	WebKit	Reporter:	Ashley Gullen <ashley>
Component:	Canvas	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	ap, dino, karlcow, webkit-bug-importer
Priority:	P2	Keywords:	InRadar, Performance
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified

Description Ashley Gullen 2023-11-17 07:35:20 PST

We make Construct, a web game engine (www.construct.net).

Using the latest Safari 17.1 on macOS Sonoma 14.1.1 with an M1 MacBook Pro, it seems canvas games rendering with WebGL and scheduled with requestAnimationFrame look janky. Here are two demos, the first using standard HTMLCanvasElement and the second using OffscreenCanvas in a web worker:

https://downloads.scirra.com/labs/flyingalong-dom/
https://downloads.scirra.com/labs/flyingalong-worker/

In both cases simply hold a touch/mouse button to move the player up.

Both cases should scroll perfectly smoothly (it is light content so the system should not be under any serious load). Both Chrome and Firefox can render it nice and smoothly. However both cases look janky with irregular frame scheduling in Safari only. Safari should be able to achieve the same smooth rendering that Chrome and Firefox can on the same system.

Comment 1 Radar WebKit Bug Importer 2023-11-19 18:16:57 PST

<rdar://problem/118632792>